I can comment on this one from personal experience. My daughter has a rare syndrome which causes her to be permanently starving hungry, no matter how much she has eaten, therefore her access to food must be restricted, it must be locked away. She also has type 2 and is on both basal and bolus insulin as well as other meds, including Metformin.
5 years ago when she was 20, she was attending an art group for people with learning disabilities. I always made her a packed lunch, so I knew what she was eating (her calorie intake has to be strictly controlled). I got a (rather hysterical) call at home telling me that she was ill and that an ambulance had been called for her, she was pale, sweating, shaky and her heart was racing. I managed to find out what had happened in the lead up to this - she had said she was going to the loo and when she didn't come back after 15 minutes, the manager went to see if she was ok. She had managed to get into the staff food cupboard (left unlocked) found a large packet of custard creams, and had eaten the lot. When the ambulance came her bg was off the scale.
She required extra insulin at A&E and was there for most of the evening, about 6 or 7 hours - I can't recall if it was administered on a couple of occasions that night but she had made herself pretty ill.
I know the circumstances are unusual but it can happen. People with diabetes who have serious weight issues can eat large amounts of carby/sweet foods and their levels can shoot up making them quite ill indeed - I agree about the overkill in dramatic programmes but it's not always completely far fetched.